This relates generally to fabrication of integrated circuits, and more particularly to fabrication of an inductive component on a backside of a semiconductor die.
Occasionally, a circuit that is implemented within an integrated circuit (IC) requires an inductive component. An inductive component may be fabricated by forming a coil on one or more of the metal layers of the IC; however, the inductance of such a component is limited to a relatively low value. However, the quality factor of in inductor formed in the metal layers of the IC may be limited given the very high resistance per square of a typical metal layer. Typically, such an inductor may only be useful for ultra high frequency (UHF) circuits, such as 300 MHz-3 GHz frequency range. Furthermore, they may contribute to significant switching losses.
Currently, silicon ICs such as switch-mode DC-DC converters use co-packaged discrete inductors which are large and bulky, contribute to package complexity, and may be a large percentage of the package cost.